1. Field of the Invention
It is well-known that animals, e.g., cattle, dogs, and swine, as well as poultry, often suffer from infectious diseases caused by viruses. Such diseases result in serious economic losses to the owners of such animals and poultry. Effective methods of moderating the effects of or preventing these viral infections and diseases are continuously sought in order to reduce the economic losses.
2. Description of the Prior Art
In the prior art, U.S. application Ser. No. 569,740, filed Apr. 21, 1975, describes antibiotic A-28086 complex, a process for its preparation, and methods for the separation of the complex into antibiotic factors A-28086A, A-28086B, and A-28086D. The reference also teaches that the A-28086 compounds are anti-coccidial, antifungal, antibacterial, anti-PPLO, insecticidal and acaricidal, as well as anti-viral agents. In particular, A-28086 factor A, also referred to as A-28086A, is active against Type III poliovirus, vaccinia virus, herpes virus and Semliki Forest virus. In addition, antibiotic A-28086A is also taught as being active against Transmissible Gastroenteritis virus, Newcastle Disease virus, and Infectious Bovine Rhinotracheitis virus. All of these activities have been demonstrated by tissue-culture tests.
Follett et al., In "The Mode of Action of Rifamycins and Related Compounds on Poxvirus," appearing in Advances in Virus Research, Vol. 18, edited by Lauffer et al., teach that the antibiotic rifamycin S was an active antiviral against vaccinia virus, but the amount of drug required for complete inhibition was too high for clinical use. The effect of the drug was reported as being specific and not the result of a toxic effect of the drug on host cell metabolism. Rifamycin is not classified as a polyether inophorous antibiotic.